This invention relates to the art of straightening the leads extending axially outward from electronic components such as resistors, diodes, chemical capacitors and the like. There exist machines for straightening the leads of axial lead components to provide leads that are straight to a high degree of precision. Such devices are currently in use. They have a substantial drawback: unless the leads are reasonably straight to begin with they cannot be handled by these machines. Unfortunately, in the processing of electrical components a large number of components with very badly bent leads gather from time to time. Before they can be processed by conventional lead straighteners, they must be prestraightened by hand. There is a great need for a device, such as disclosed herein, to process components with badly bent leads to straighten the leads at least sufficiently to enable them to be processed by the available precision straighteners.
A number of patented devices are designed to roll the leads between two surfaces in close proximity: Frank et al. U.S. Pat. No. 2,860,686 discloses a component lead straightener device having a notched wheel with extensions to each side. Facing the extension of the wheel are surrounds. Continuously moving belts move over the surface of the surrounds. The component leads must be sufficiently straight to enter the space between the extensions and the belts. The surrounds vibrate to hammer the leads into straightness.
Ainsworth et al. U.S. Pat. No. 2,867,262 teaches rolling the leads between an inner and outer cylindrical surface. Peterson et al. U.S. Pat. No. 2,878,841 teaches rolling leads between two planar surfaces, one surface being the face on a rotating disk. Rus U.S. Pat. No. 3,002,539 discloses a lead straightener which rolls the leads between two rolls while the lead is held at the closest distance between the two rolls. Campbell et al. U.S. Pat. No. 3,348,586 teaches rolling leads between flat belts and rails that are angled toward the entry point so that the leads will be straightened starting adjacent the component and thence axially outward. Bryner et al. U.S. Pat. No. 3,633,643 teaches a device for rolling leads between drums and matching surrounds.
Swanson U.S. Pat. No. 3,739,819 teaches rolling leads against a surround by a frustrum-shaped roller. The surround is conical shaped. This patent claims the apparatus disclosed is able to handle badly bent leads. However, it would appear that it cannot handle the very severely bent leads often encountered. DuBois U.S. Pat. No. 3,744,535 teaches an apparatus for rotating the component body with the leads extending into an ever narrowing space between two surround surfaces. A characteristic of most, if not all, of the devices described so far is that the leads are moved between two surfaces and sometimes are rolled therebetween. Since the surfaces must be close together to perform their function, the leads must be reasonably straight to begin with or they cannot be fed between the surfaces.
Martin et al. U.S. Pat. No. 3,892,263 discloses a lead straightener for severely bent leads comprising first and second corkscrew elements that rotate in opposite directions to grab opposite extending leads before moving apart. The Martin et al. device is not easily adaptable to processing parts rapidly. Note that only one component is being processed at a given instance.
Braden U.S. Pat. No. 3,948,298 discloses a lead straightener that supposedly grabs the leads near the component and pulls away while rotating. With this device, as with Martin et al., only one component is being processed at a given instance.
It is an advantage according to this invention to provide a device for straightening the leads of axial lead components that are severely bent, for instance, bent more than 90 degrees, automatically with very little manual labor and at a high rate (parts per unit time).